Methods

A multi‐centre, randomised, blinded, controlled trial carried out at 27 hospital obstetric units in the UK.

Participants

3420 women undergoing all types of operative vaginal birth at 36 weeks or greater gestation.

Women were excluded if they had any clinical indication for antibiotic administration after delivery, third‐degree or fourth‐degree perineal tears, receipt of antenatal or intrapartum antibiotics with ongoing antibiotics after delivery or a known allergy to penicillin or any of the components of amoxicillin and clavulanic acid, or who had a history of anaphylaxis to another β‐lactam agent.

Setting: 27 hospital obstetric units in the UK; 13 March 2016, and 13 June 2018.

Interventions

A single dose of intravenous amoxicillin and clavulanic acid (1 g amoxicillin and 200 mg clavulanic acid) as soon as possible and no more than 6 hours after giving birth (n = 1715) or placebo group using 20 mL of intravenous sterile 0.9% saline within the same timeframe (n = 1705).

Outcomes

Primary outcomes were a confirmed or suspected maternal infection within 6 weeks of delivery as defined as a new antibiotic prescription for a presumed perineal wound‐related infection, endometritis or uterine infection, urinary tract infection with systemic features (pyelonephritis or sepsis) or other systemic infection (clinical sepsis); confirmed systemic infection on culture; or endometritis required at least 1 of the following criteria to be met‐organisms were cultured from fluid (including amniotic fluid) or tissue from endometrium obtained during an invasive procedure or biopsy, or the woman exhibited at least 2 of fever (> 38 degrees Celsius), abdominal pain, uterine tenderness, or purulent drainage from uterus (with no other recognised cause for the latter 3 symptoms).

Secondary outcomes assessed within 6 weeks of delivery were: systemic sepsis, perineal wound infection, perineal pain, use of pain relief, hospital bed stay until discharge, need for additional perineal care, dyspareunia, ability to sit comfortably to feed the baby, maternal health‐related quality of life, breastfeeding, wound breakdown, intervention side effects, healthcare resource use and costs, or adverse events.

Notes

Dates study conducted: the trial was carried out between 13 March, 2016 and 13 June 2018.

Funding sources for the study: NIHR Health Technology Assessment programme.

Declarations of interest among primary researchers: 4 authors declared receipt of funding from NIHR outside the submitted work. All other authors have no competing interests to declare.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

Permuted blocks of variable size was used for random sequence generation.

Allocation concealment (selection bias)

Low risk

Sealed, sequentially‐numbered, indistinguishable packs containing active drug or placebo as designated randomisation list performed by an independent trials programmer.

Blinding of participants and personnel (performance bias)
All outcomes

Low risk

Women and most clinicians including research midwives and those taking consent were masked to allocation either intervention or placebo.

Blinding of outcome assessment (detection bias)
All outcomes

Low risk

Midwives, nurses, or doctors collecting outcome information were masked to allocation either intervention or placebo.

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Primary outcome data were complete. Secondary outcome data were incomplete with 24% loss to follow‐up; however, it was balanced between both groups.

Selective reporting (reporting bias)

Low risk

Outcomes were reported as in the study protocol.

Other bias

Low risk

Study appeared to be free of other sources of bias.

Methods

Selected by randomisation table to receive treatment or no treatment; not blinded or placebo‐controlled.

Participants

393 women undergoing instrumental deliveries (either vacuum or forceps deliveries).

Women were excluded if they had evidence of chorioamnionitis, or other infections, or if they were allergic to penicillin or cephalosporins.

Setting: University Hospital of Jacksonville, USA; September 1986 to February 1988.

Interventions

2 g of cefotetan intravenously after cord clamping (n = 192) or no treatment (n = 201).

Outcomes

Endomyometritis (at least 1 rise in oral temperature greater than 38.1 degrees Celsius after the first 24 hours of delivery and uterine tenderness or foul‐smelling lochia with no clinical or laboratory evidence confirming another source of the fever).

Notes

Dates study conducted: the trial was carried out between September 1986 and February 1989.

Funding sources for the study: the funding sources of an included study could not be identified.

Declarations of interest among primary researchers: not reported.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

A randomisation table was used for random sequence generation.

Allocation concealment (selection bias)

Unclear risk

Allocation concealment could not be interpreted.

Blinding of participants and personnel (performance bias)
All outcomes

Unclear risk

Information not clearly mentioned.

Blinding of outcome assessment (detection bias)
All outcomes

Unclear risk

Who measured the outcome was not mentioned.

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Same number of samples at intervention given and outcome measure.

Selective reporting (reporting bias)

Unclear risk

The study protocol was not available, so there was insufficient information to permit judgement.

Other bias

Low risk

Study appeared to be free of other sources of bias.